Device use indicator

Abstract

A device use indicator ( 16 ), which is designed to signal a predetermined amount of use of a device as a function of the amount of vibration of the device is provided. The indicator is adapted to be coupled or attached to a device ( 10 ). The indicator includes a first disk ( 18 ), a second disk ( 20 ), and an intermediate layer ( 22 ) separating the first disk from the second disk. The first disk retains a chemical therein. In operation, when the device to which the use indicator is attached is used, vibration of the device and the indicator triggers release of the chemical from the first disk. The chemical then travels through the intermediate layer to be received by the second disk. The chemical, when received by the second disk in excess of a predetermined amount, creates a detectable indication. The detectable indication, for example, a color or shade change produced in the second disk, signals a user that the device has been used for a predetermined amount of time as a function of the amount of its vibration.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:  
     
       1. A device use indicator for coupling to a device, the use indicator when coupled to the device signaling a predetermined amount of use of the device as a function of an amount of vibration of the device, the use indicator comprising: 
       a first disk retaining a first chemical therein, the first disk being adapted to release the first chemical therefrom upon vibration of the first disk;  
       a second disk adapted for receiving the first chemical released from the first disk; and  
       an intermediate layer separating the first disk from the second disk;  
       wherein the first chemical retained in the first disk, when received by the second disk in excess of a predetermined amount, creates a detectable indication of use of the device the predetermined amount being above zero.  
     
     
       2. The use indicator of claim  1 , in combination with the device to which the use indicator is coupled, wherein the device is a power toothbrush including a toothbrush body and a brush head that is removably coupled to the toothbrush body, and the use indicator is a brushwear indicator attached to the brush head of the power toothbrush. 
     
     
       3. The use indicator of claim  1 , wherein the detectable indication is a visible change. 
     
     
       4. The use indicator of claim  3 , wherein the visible change is a color or shade change. 
     
     
       5. The use indicator of claim  1 , wherein the second disk retains a second chemical therein, and receipt of the first chemical released from the first disk by the second disk produces a chemical reaction within the second disk to cause the detectable indication. 
     
     
       6. The use indicator of claim  5 , wherein the first chemical and the second chemical comprise an acid and a base, or a base and an acid, the chemical reaction being an acid-base titration, and the second disk further including a pH-indicating dye. 
     
     
       7. The use indicator of claim  6 , wherein the base comprises sodium bicarbonate, the acid comprises acetic acid, and the pH-indicating dye comprises phenol red. 
     
     
       8. The use indicator of claim  5 , wherein the chemical reaction is selected from a group consisting of a chemical oxidation-reduction reaction, an addition reaction, a subtraction reaction, and an initiation of an enzymatic reaction. 
     
     
       9. The use indicator of claim  5 , wherein the first chemical is a liquid, the second chemical is a liquid, and the chemical reaction forms a gas from the liquids to create pressure to produce a detectable indication. 
     
     
       10. The use indicator of claim  1 , wherein the intermediate layer comprises an annular spacer defining a gap between the first and second disks, across which the first chemical released from the first disk migrates to the second disk. 
     
     
       11. The use indicator of claim  10 , wherein the gap is filled with a barrier material. 
     
     
       12. The use indicator of claim  1 , wherein the first and second disks comprise porous hydrophilic material selected from a group consisting of sintered glass, foamed glass, sintered metal, ceramic, polyethylene, polypropylene, and nylon. 
     
     
       13. The use indicator of claim  1 , wherein the intermediate layer comprises material selected from a group consisting of nylon, polyester, and fluoroethylenes. 
     
     
       14. A method of notifying a user of a predetermined amount of use of a device as measured by vibration of the device, the method comprising the steps of: 
       (a) coupling a use indicator to the device, the use indicator comprising:  
       (i) a first disk retaining a first chemical therein,  
       (ii) a second disk, and  
       (iii) an intermediate layer separating the first disk and the second disk;  
       (b) using the device and the use indicator;  
       (c) transferring the first chemical in response to vibration of the device from the first disk across the intermediate layer to the second disk; and  
       (d) producing a detectable indication of use of the device when the first chemical is received by the second disk in excess of a predetermined amount the predetermined amount being above zero.  
     
     
       15. The method of claim  14 , wherein the device to which the use indicator is coupled is a power toothbrush including a toothbrush body and a brush head that is removably coupled to the toothbrush body, and the use indicator is a brushwear indicator attached to the brush head. 
     
     
       16. The method of claim  14 , wherein the detectable indication is a visible change. 
     
     
       17. The method of claim  16 , wherein the visible change is a color or shade change. 
     
     
       18. The method of claim  14 , wherein the second disk retains a second chemical therein, and the production of a detectable indication comprises producing a chemical reaction between the first chemical and the second chemical within the second disk. 
     
     
       19. The method of claim  18 , wherein the first chemical and the second chemical comprise an acid and a base, or a base and an acid, the second disk further including a pH-indicating dye, and the production of a chemical reaction comprising an acid-base titration that visibly changes the color or shade of the pH-indicating dye in the second disk. 
     
     
       20. The method of claim  19 , wherein the base comprises sodium bicarbonate, the acid comprises acetic acid, and the pH-indicating dye comprises phenol red. 
     
     
       21. The method of claim  18 , wherein the chemical reaction is selected from a group consisting of a chemical oxidation-reduction reaction, an addition reaction, a subtraction reaction, and an initiation of an enzymatic reaction. 
     
     
       22. The method of claim  18 , wherein the first chemical is a liquid, the second chemical is a liquid, and the chemical reaction forms a gas from the liquids to create pressure to produce a detectable indication. 
     
     
       23. The method of claim  14 , wherein the intermediate layer comprises an annular spacer defining a gap between the first and second disks, across which the first chemical released from the first disk migrates to the second disk. 
     
     
       24. The method of claim  23 , wherein the gap is filled with a barrier material. 
     
     
       25. The method of claim  14 , wherein the first and second disks comprise porous hydrophilic material selected from a group consisting of sintered glass, foamed glass, sintered metal, ceramic, polyethylene, polypropylene, and nylon. 
     
     
       26. The method of claim  14 , wherein the intermediate layer comprises material selected from a group consisting of nylon, polyester, and fluoroethylenes.